First build - A little input?

Hi. I was hoping to get a little input on my proposed first build below. I’d like to know if all these parts will work well together in general and specifically for HD video editing. Beyond editing, I mainly use my computer to download a steady stream of movies, etc, while surfing the net and watching video.

I’ve cherry picked what I consider to be the best parts that I want, but I want to make sure the sum of those parts isn’t less than the whole, if that makes sense. In other words, the parts may look good on paper, but together will they be a great machine or incompatible, etc?

I would say that all of your hardware looks pretty good (I can't really judge the motherboards though, don't know a ton about mobos). Depending on your video editing software, you may consider putting two gts450's in SLI because you can get 2 for just below 200. If you editing software won't use both of the cards then its not really worth it. Here is a link to the gts 450 for 102 after rebate including shipping.